CHEVRON...DID IT....no diff.circuitsmith wrote:FIrst, dump a bottle of Chevron Techron in the gas tank.
Next, check valve clearances.
Third, do a compression test.
Not able to help yet, but that highlighted item has me wondering what that is?jasonvibe wrote:CHEVRON...DID IT....no diff.circuitsmith wrote:FIrst, dump a bottle of Chevron Techron in the gas tank.
Next, check valve clearances.
Third, do a compression test.
VALVE CHECK ...DID IT... all center of specs. And I changed the spark plugs.
Since Valve check is OK done by me, and does not burn any oil between oil changes...so no compression check done.
I did check the MAF reading at idle on my PC program. It was 1.8 gm/sec. Meaning it's sucking air in past the MAF within spec. 1.4 to 2.0.
Another thing I did was check the EVAP system.When the issue happens it's warm. There is a test in the manual for EVAP system. And FACT the EVAP runs more in warm weather driving than cold weather. I did the test. It easily passed the "pressure test". Manual says give it 5 minutes. I had NO leaks pressure drop... after doing this test for 20 min.
Also a nother note: I rarely get a "swoosh" when removing the gas cap...UNLESS there is a significant change in temperatures. EX: car shut off 6pm 90 degrees and Then in the morning I remove the gas cap it's 60 degrees prior to heading out, or happen to go to the gas station 1st stop in the AM. This seems normal. aka gas cap good.
TURNING THE BLOWER On high idles goes down a bit. That is due to alternator load. The ECM/idle air control does compensate for it mostly. But blower motor or not, the idle drops below spec after six seconds. And more noticeable with blower on. But it's normal prior to the 6 second "time up". It surely does not go up. ALSO any vacuum leak between the MAF and the engine itself cannot be fully compensated for by the ECM. Trust me on this one. That voltage idea tends to make sense. But I did check the voltage a while back last year. I made a special connector to plug from access outlet into my voltmeter. Oh and I even bought a NEW alternator...thinking voltafge. Made no diff. And lucky they let me return it because the new one was a noisy alternator. So I still have the original in. I will check Voltage again. Also I have a new battery last year. The original battery was still GOOD. But at 7 years old...was pushing it. YES, I am able to plug into the OBDII port with my laptop and monitor many things. with the special PC program I have. I hope this clears PC program question up. But I think I may have found something. It seems when the EVAP is going -clicking( which can only be heard when hood up-normal) the idle is...poorer than no EVAP going aka- cold engine. EVAP clicks all the time once the car is warmed up . Again this has always been like this. AS stated earlier I did check for EVAP system and solenoid valve for leaks. But there is something I am missing...I think. Could the charcoal canister be wasted under the gas tank cause this ? But I have no codes thrown out...circuitsmith wrote:The ECM should be adjusting the idle to spec in 6+ seconds, even with a leak etc. "pushing/pulling" it.
Check the battery voltage next time the idle gets down and dirty. DC and AC ripple.
Does turning the blower (no AC) to high make the low idle go up?
I just have a hunch...
Can you be more specific about the program you use and how you connect your PC to the OBDII ? I'd like to do the same thing for diagnosing my cars if it isn't too expensive.jasonvibe wrote: YES, I am able to plug into the OBDII port with my laptop and monitor many things. with the special PC program I have. I hope this clears PC program question up.
+1Chiadog wrote:Can you be more specific about the program you use and how you connect your PC to the OBDII ? I'd like to do the same thing for diagnosing my cars if it isn't too expensive.jasonvibe wrote: YES, I am able to plug into the OBDII port with my laptop and monitor many things. with the special PC program I have. I hope this clears PC program question up.